Ahnentafel Explained

Ahnentafel is a word commonly used in genealogy although it probably confuses most newcomers. Ahnentafel is a German word that literally translates as “ancestor table”. It is a list of all known ancestors of an individual and includes the full name of each ancestor as well as dates and places of birth, marriage, and death whenever possible. It also has a strict numbering scheme.

Once the reader is accustomed to ahnentafels, it becomes very easy to read these lists, to move up and down from parent to child and back again, and to understand the relationships of the listed people. Ahnentafels are very good at presenting a lot of information in a compact format. However, the numbering system is the key to understanding ahnentafels.

To visualize the numbers, first consider this typical pedigree chart:

Carefully observe the numbers in the above chart. You will notice that every person listed has a number and that there is a mathematical relationship between parents and children. The number of a father is always double that of his child’s. The number of the mother is always double that of her child’s plus one. The number of a child is always one-half that of a parent (ignoring any remainder).

In the above example, the father of person #6 is #12 (the father is double the child’s number). The mother of #6 is #13 (the mother is double plus one of the child’s). The child of #12 and #13 is #6 (the child is always one-half the parent’s number, ignoring remainders).

Now, let’s take the above chart and write it in ahnentafel format:

person

father

mother

paternal grandfather

paternal grandmother

maternal grandfather

maternal grandmother

great-grandfather

great-grandmother

great-grandfather

great-grandmother

great-grandfather

great-grandmother

great-grandfather

great-grandmother

Notice that the numbers are exactly the same as in the pedigree chart. The rules of father=2 times child, mother=2 times child+1, child=one-half of parent, etc., remain the same. This is an ahnentafel chart.

For a more detailed example of an ahnentafel, here’s an excerpt from the ahnentafel of one well-known American:

The above examples show information about 15 individuals, but ahnentafels typically contain information about many more people than this. You can often find ahnentafels that list hundreds or even thousands of individuals, all ancestors of person #1 in the list. For instance, a much longer ahnentafel for President Bush may be found at: http://www.wargs.com/political/bush.html.

Notice that the mathematical rules about relationships shown in the pedigree chart still apply in the ahnentafel chart. Also, the true ahnentafel lists the person’s full name, along with dates and places of birth, marriage, and death, if known.

All modern genealogy programs can produce ahnentafel charts. Of course, you could also create an ahnentafel chart by hand or by using a word processor. Whatever method you choose, an ahnentafel is an easy method of presenting a lot of ancestral data in a compact format.

I use a “modified” version of Ahnentafel for my ancestors, and I love the result. I append a dash and a number. -0 for the direct ancestor and -01 and up for each of his/her siblings. Example, my mother’s siblings are 3-01, 3-02, 3-03, etc. I have only worked on gathering direct ancestors, and their children’s information. I do not do in-laws or children of siblings other than an occasional note of names and dates. Every file I save is named starting with the Ahnentafel number followed by _Firstname-Lastname. If I have a file to save for a spouse of a sibling, I add a $ after the number (3-4$, would be my aunt’s husband, 3-4$b for 2nd-husband. When saving files there are subfolders for the different categories (Birth, Death, Marriage, Military, Obits, Tombstones, etc). I can easily find a file for any person by the subfolder and starting number. The census files are saved starting with the Head-of-Household’s AHN number, census-year & HOH’s name. Every printed copy has their AHN-number included. This has made it so easy for me to find files for any ancestor.

I have a similar system which works for me although I’m getting into very large numbers now. I add in the alphabet though instead of numbering the siblings. And I alternate roman numberls and numbers each generation and no dash. Makes it complicated if you didn’t start that way! Example – R14 Biii b1 a2 is my grandmother’s nephew. I add the # symbol for a spouse. Otherwise is use folders and documents etc. the same as you. Sure makes it easy to look up who they are if you can’t remember. Numbers have always been a mystery to me so adding in the alphabet helps me. So pleased to see someone else with a different system.

Dick – Thanks so much for posting this. This is very informative. I did notice that all of the males have even numbers and all the females have the odd numbers – not sure if anyone made that connection. This is great for tracking the direct line, but my question would be – how do you track siblings? I wouldn’t want to leave anyone out of my ‘tree’, nuts and all. Would you do an ahnentafel for each sibling? That might create quite a cumbersome filing system. Any suggestions from any of the readers?

—> I did notice that all of the males have even numbers and all the females have the odd numbers

Except for person #1. That obviously is an odd number regardless if it is male or female.

—> This is great for tracking the direct line, but my question would be – how do you track siblings?

You don’t. Ahenetafel is the German word for “ancestor table” meaning a list of one’s ancestors. It only lists ancestors. If you want to list siblings, cousins, descendants, or others, you need a different report, not an ahnentafel.

Re siblings in an Ahnentafel: To repeat Richard Eastman (above):
You don’t (put siblings in an Ahnentafel). To paraphrase, an Ahnentafel, whether in a pedigree chart or a report form, starts with one individual and looks backward in time. It shows that person’s direct ancestors, only.
To show all members — siblings and spouses and their children, et al — of each generation, you have your genealogy program generate a “Descendant Report” (that’s what it is called in the Family Tree Maker program). You select one person early in time as the beginning point. The report lists all descendants of that person (and his/her spouse). The report “comes forward”, if you will, to the present day, or as far as your research has gone. Descendant reports have various ways of numbering/identifying individuals; won’t get into that here.

—> Does this system tell me the relationship between person no. 1 and person no.33 ?

Yes. In an ahnentafel chart, each person has a number. To find the father of a person, multiple the persons number by two. To find the mother of a person, multiple the persons number by two and then add one. To find the child of a person, divide the person’s number by two and ignore any remainder.

He has been involved in genealogy for more than 35 years. He
has worked in the computer industry for more than 50 years in hardware,
software, and managerial positions. By the early 1970s, Dick was already
using a mainframe computer to enter his family data on punch cards. He
built his first home computer in 1980.